William g



NITED STATES PATENT OFFICE.

WVILLIAM G. FUERTH, OF NElVARK, NEW JERSEY, ASSIGNOR TO THE POMEROYDUPLICATOR COMPANY, OF SAME PLACE.

DUPLICATING STENCILING MATERIAL.

SPECIFICATION forming part of Letters Patent No. 467,890, dated January26, 1892.

Application filed October 9, 1890. Serial No. 367,578. (No specimens.)

T 0 M6 whom it may concern:

Be it known that I, IVILLIAM G. FUERTH, a citizen of the United States,residing at Newark, in the county of Essex and State of New Jersey, haveinvented certain new and useful Improvements in Typographing StencilingMaterial, of which the following is a full and clear description, suchas will enable others skilled in the art to which the invention relatesto make and use the same.

My invention relates to the preparation of material used in connectionwith a type-writer or stylus and any reduplicating machine or apparatusfor reproducing type-written or other matter requiring fac-similereproduction; and my invention consists, essentially, in coating a sheetof porous fibrous paper or fabric with a material formed by combining amarine wax with fixed oils, fats, or fatty acids, the said sheet when socoated being impervious to ink or coloring-fluids and the coating beingreadilyextracted byother sheets placed against the coated sheet andreceiving the impact of the character of the type-writer or point of thestylus.

In carrying out my invention I first prepare a compound by meltingtogether spermaceti, sperm-oil, bottle-nose oil, or other analogoussubstances derived from the allied species of salt-water fish, withfixed oils, fats, or fatty acids. The proportion of these marine waxesmay be varied to suit the climate and other conditions. For instance, incold weather I prefer to use the more fluid waxes, such as sperm-oil,which may be in the proportion of six per cent. to the whole mass, moreor less, while in the case of spermaceti, which is preferably used inwarm weather, the proportion may exceed the other ingredients. For i11-stance, the proportion of spermaceti may with advantage fully equal thatof all the other bodies composing the material. fibrous sheet isimmersed in this liquid compound and slowly removed therefrom to permitthe surplus material to run off when a uniform coating is transferred tothe sheet. 200 Fahrenheit has been found a suitable temperature toinsure a specific density and limpidity of the compound to enable one toobtain a perfect and uniform coating on the The porous sheet; but I donot limit myself to this exact temperature, but would state that if atemperature much in excess of that given is used the compound wouldbecome too liquid or thin and would pass through the pores of thefibrous paper,instead of uniformly filling the same.

In the present state of the art sheets of porone paper are pressed androlled while their paraffine coating is in a soft or plastic state, sothat the fiber of the paper and the impressed coating form a homogeneousand inseparable mass, causing the common and undesirable abrasion orperforating of the paper during the process of utilizing the sheets forreproducing purposes, whether the stencil be produced by a type-writeror stylus, and in case of non-edged or full-faced contacting charactersthe surface which is so pressed as above described will offer such asolid resistance to the contacting character as to defeat the productionof a clear fac-simile. In addition to the above the packing of thiscoating within the indentures forms an obstruct-ion to the free passageof the ink. A keen-edged character will perforate and injure the fiberof the paper, while a loop character will in many instances be outentirely out.

In my invention I preferably coat both sides of the fibrous paper withmy compound and remove the same by the aid of extractorsheets placed infront and rear of the coated sheet without in any manner attacking thefiber or structure of the paper by the friction of the contactingcharacters.

The compositions now used for coating sheets for stencil purposes arealmost wholly composed of what is improperly termed Waxes such asparaifinewith a varying adulteration of fixed oils to produce the properstate of pliability, and which addition of fixed oils or hydrocarbonsreduced the fusion or melting point to so low a degree of temperature asto make it practically useless during warm or even moderately-heatedtemperatures, thereby causing the contacting faces of the coated sheetsto stick or cohere and invariably to become plastic at a much lowerdegree of heat than would be required to fuse the same material.

The principal difficulty arising from the heretofore-coated sheets wasoccasioned by th 0 coating cracking or becoming fractured when handlingor removing one sheet from another, as particles of the paraffine on onesheet would cohere to those of another and be indiscriminatelytransferred from one sheet to the other, thereby opening up the pores inthe paper, rendering the sheet pervious to the ink, and practicallydestroying its usefulness. When packed together, the weight of thesheets would often cause the paraffiue to soften and cohere, therebydestroying their utility.

The cohesive property of paraffine is such as to make it a practicalimpossibility to prepare stencils without displacing or pe forating andeventuallydestroying the fiber of the paper, as the paraffine alsoadheres directly to the fine fibers, and when the character strikes theparaffine it pulls the same .away within the lines of the character andalso tears away the fiber at the point where the contact is made, thusperforating the paper and permitting the loop characterssuch as 0 p b,&c.'t0 be entirely out out, allowing theink to pass through the cut-outportion, destroying the stencil-sheet, and making unsightly andundesirable copies.

In my invention the marine waxes named, when mixed with the fixed oils,fats, or fatty acids, have the effect of greatly modifying and lesseningthe adhesive and cohesive properties incident to the paraffine-coatedsheets as at present made, as the spermaceti or spermoil produces afinely-granular condition which enables the material to fracture andbreak in sharp lines along the lines of the contacting character, andwill thereby enable exterior non-coated sheets to extract or take offthe material, so as to leave the fibers of the paper intact andundisturbed. In addition to this there can be no cohesion of sheetsplaced face to face, and therefore single sheets may in ordinarytemperatures be readily separated from the pile without causing anabrasion or disturbance of the surfaces of the sheets.

The term marine wax as used by me in this description is meant to referto the several products derived from the cavities of salt- Water fish. 4

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. Acomposition of matter forcoatingsheets for stencil purposes,consisting, essentially, of a marine wax, combined with fixed oils,fats, or fatty acids.

2. A sheet of fibrous material coated or covered with a compositionconsisting of spermaceti or analogous product derived from the alliedspecies of fish, combined with fixed oils, fats, or fatty acids.

XVILLIAM G. FUER'lI-I.

Witnesses:

J. A. BEEcHER, R. H. DEAN.

